U.S. patent number 11,309,967 [Application Number 16/923,383] was granted by the patent office on 2022-04-19 for communications network and related device.
This patent grant is currently assigned to Huawei Technologies Co., Ltd.. The grantee listed for this patent is HUAWEI TECHNOLOGIES CO., LTD.. Invention is credited to Chaojun Deng, Liankui Lin.
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United States Patent |
11,309,967 |
Deng , et al. |
April 19, 2022 |
Communications network and related device
Abstract
This application discloses a communications network and a
related device. In one embodiment, the communications network
includes a first optical line terminal and a second optical line
terminal. The first optical line terminal is configured to send,
through a first passive optical network (PON) interface based on a
first PON protocol, a first optical signal to the at least one
second optical line terminal. The second optical line terminal is
configured to process the first optical signal and send through a
second PON interface based on a second PON protocol, a processed
first optical signal to at least one customer-premises equipment
during downstream data transmissions, and process a second optical
signal and send, through the first PON interface based on the first
PON protocol, the processed second optical signal to the first
optical line terminal during upstream data transmissions.
Inventors: |
Deng; Chaojun (Dongguan,
CN), Lin; Liankui (Dongguan, CN) |
Applicant: |
Name |
City |
State |
Country |
Type |
HUAWEI TECHNOLOGIES CO., LTD. |
Guangdong |
N/A |
CN |
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Assignee: |
Huawei Technologies Co., Ltd.
(Guangdong, CN)
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Family
ID: |
1000006247896 |
Appl.
No.: |
16/923,383 |
Filed: |
July 8, 2020 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200343975 A1 |
Oct 29, 2020 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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PCT/CN2018/122230 |
Dec 20, 2018 |
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Foreign Application Priority Data
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Jan 17, 2018 [CN] |
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201810046574.0 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04B
10/272 (20130101); H04Q 11/0067 (20130101); H04Q
2011/0096 (20130101) |
Current International
Class: |
H04B
10/272 (20130101); H04Q 11/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
1547335 |
|
Nov 2004 |
|
CN |
|
1855778 |
|
Nov 2006 |
|
CN |
|
1855778 |
|
Nov 2006 |
|
CN |
|
101459656 |
|
Jun 2009 |
|
CN |
|
102377479 |
|
Mar 2012 |
|
CN |
|
104519420 |
|
Apr 2015 |
|
CN |
|
1128585 |
|
Aug 2001 |
|
EP |
|
2164221 |
|
Mar 2010 |
|
EP |
|
2010537600 |
|
Dec 2010 |
|
JP |
|
2012178884 |
|
Sep 2012 |
|
JP |
|
2016501466 |
|
Jan 2016 |
|
JP |
|
2601124 |
|
Oct 2016 |
|
RU |
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2015134789 |
|
Sep 2015 |
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WO |
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2017223235 |
|
Dec 2017 |
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WO |
|
Other References
PCT International Search Report and Written Opinion issued in
International Application No. PCT/CN2018/122230 dated Feb. 27,
2019, 13 pages (with English translation). cited by applicant .
Office Action issued in Chinese Application No. 201810046574.0
dated Feb. 1, 2021, 11 pages. cited by applicant .
Extended European Search Report issued in European Application No.
18901396.4 dated Feb. 9, 2021, 21 pages. cited by applicant .
Hasegawa et al., "Transmission Characterization in Active Optical
Access System," Institute of Electronics, Information and
Communication Engineers, Technical Report vol. 109, No. 399, Japan,
dated Jan. 28-29, 2010, 9 pages (English abstract). cited by
applicant .
Office Action issued in Japanese Application No. 2020-535204 dated
Sep. 21, 2021, 5 pages (with English translation). cited by
applicant .
Office Action issued in Russian Application No. 2020126912/07 dated
Dec. 8, 2021, 27 pages (with English translation). cited by
applicant.
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Primary Examiner: Wolf; Darren E
Attorney, Agent or Firm: Fish & Richardson P.C.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of International Application No.
PCT/CN2018/122230, filed on Dec. 20, 2018, which claims priority to
Chinese Patent Application No. 201810046574.0, filed on Jan. 17,
2018. The disclosures of the aforementioned applications are hereby
incorporated by reference in their entireties.
Claims
What is claimed is:
1. A communications network, comprising a first optical line
terminal, at least one second optical line terminal, and at least
one customer-premises equipment; the first optical line terminal
comprises: at least one processor; and a memory coupled to the at
least one processor and storing programming instructions for
execution by the at least one processor, the programming
instructions instruct the at least one processor to send, through a
first passive optical network (PON) interface based on a first PON
protocol, a first optical signal to the at least one second optical
line terminal; a second optical line terminal of the at least one
second optical line terminal comprises: at least one processor; and
a memory coupled to the at least one processor and storing
programming instructions for execution by the at least one
processor, the programming instructions instruct the at least one
processor to: denoise the first optical signal; and send through a
second PON interface based on a second PON protocol, the denoised
first optical signal to the at least one customer-premises
equipment during downstream data transmissions; and process a
second optical signal; and send, through the first PON interface
based on the first PON protocol, the processed second optical
signal to the first optical line terminal during upstream data
transmissions; and each of the at least one customer-premises
equipment comprises: at least one processor; and a memory coupled
to the at least one processor and storing programming instructions
for execution by the at least one processor, the programming
instructions instruct the at least one processor to send, through
the second PON interface based on the second PON protocol, the
second optical signal to the second optical line terminal connected
to the at least one customer-premises equipment.
2. The communications network according to claim 1, wherein the
communications network further comprises a first optical
distribution network and a second optical distribution network; the
first optical distribution network is configured to: transmit, to
each of the at least one second optical line terminal, the first
optical signal sent by the first optical line terminal during
downstream data transmission; and transmit, to the first optical
line terminal, the processed second optical signal sent by the
second optical line terminal during upstream data transmission; and
the second optical distribution network is configured to: transmit,
to each of the at least one customer-premises equipment, the
denoised first optical signal sent by the second optical line
terminal during data downstream data transmissions; and transmit,
to the second optical line terminal connected to the at least one
customer-premises equipment, the second optical signal sent by the
customer-premises equipment during upstream data transmissions.
3. The communications network according to claim 2, wherein the
first optical distribution network comprises a first optical
splitter, and the second optical distribution network comprises a
second optical splitter; the transmit the first optical signal and
the transmit the second optical signal are performed through the
first optical splitter; and wherein the transmit the denoised first
optical signal and the transmit the processed second optical signal
are performed through the second optical splitter.
4. The communications network according to claim 3, wherein a
distance between the first optical splitter and the second optical
line terminal is less than a distance between the first optical
splitter and the first optical line terminal.
5. The communications network according to claim 3, wherein a
distance between the second optical splitter and the
customer-premises equipment is less than a distance between the
second optical splitter and the second optical line terminal.
6. The communications network according to claim 1, wherein each of
the first PON protocol and the second PON protocol is one of a
gigabit passive optical network (GPON), an Ethernet passive optical
network (EPON), a 10G GPON, 10G EPON, or a time wavelength division
multiplexing (TWDM) PON protocol.
7. The communications network according to claim 1, wherein the
customer-premises equipment is one of an optical network unit (ONU)
or an optical network terminal (ONT).
8. An optical line terminal, comprising at least one processor, a
communications apparatus configured with a first passive optical
network (PON) interface and a second PON interface, and a
non-transitory computer-readable storage medium coupled with the at
least one processor and the communications apparatus; the
non-transitory computer-readable storage medium stores programming
instructions for execution by the at least one processor, the
programming instructions instruct the at least one processor to:
denoise a first optical signal; and process a second optical
signal; and cause the communications apparatus to: receive, through
the first PON interface, a first optical signal based on a first
PON protocol; and send the denoised first optical signal based on a
second PON protocol to customer-premises equipment through the
second PON interface during downstream data transmissions; and
receive, through the second PON interface, the second optical
signal based on the second PON protocol sent by the
customer-premises equipment; and send the processed second optical
signal based on the first PON protocol through the first PON
interface during upstream data transmissions.
9. The optical line terminal according to claim 8, wherein the
optical line terminal further comprises an optical module, a first
PON media access control (MAC) chip, and a second PON MAC chip,
wherein the first PON MAC chip adopts a protocol corresponding to
the first PON interface, and the second PON MAC chip adopts a
protocol corresponding to the second PON interface; denoise the
first optical signal comprises: instructing the optical module to
convert the first optical signal into a first electrical signal,
instructing the first PON MAC chip to perform protocol deframing on
the first electrical signal, instructing the second PON MAC chip to
perform protocol framing on a first electrical signal obtained
after the protocol deframing, and instructing the optical module to
perform electrical-to-optical conversion on a first electrical
signal obtained after the protocol framing; and process the second
optical signal comprises: instructing the optical module to convert
the second optical signal into a second electrical signal,
instructing the second PON MAC chip to perform protocol deframing
on the second electrical signal, instructing the first PON MAC chip
to perform protocol framing on a second electrical signal obtained
after the protocol deframing, and instructing the optical module to
perform electrical-to-optical conversion on a second electrical
signal obtained after the protocol framing.
10. The optical line terminal according to claim 8, the programming
instructions instruct the at least one processor to: parse, based
on the first PON protocol, the first optical signal and encapsulate
a parsed first optical signal based on the second PON protocol
during downstream data transmissions; and parse, based on the
second PON protocol, the second optical signal and encapsulate a
parsed second optical signal based on the first PON protocol during
upstream data transmissions.
11. The optical line terminal according to claim 8, wherein each of
the first PON protocol and the second PON protocol is one of a
gigabit passive optical network (GPON), an Ethernet passive optical
network (EPON), a 10G GPON, 10G EPON, or a time wavelength division
multiplexing (TWDM) PON protocol.
12. A method for processing optical signals in an optical line
terminal, comprising: during data downstream transmission,
receiving, through a first passive optical network (PON) interface,
a first optical signal in a first PON protocol; denoising the first
optical signal; and sending, through a second PON interface, a
processed first optical signal in a second PON protocol to
customer-premises equipment; and during data upstream transmission,
receiving, through the second PON interface, a second optical
signal in the second PON protocol from the customer-premises
equipment; processing the second optical signal; and sending,
through the first PON interface, a processed second optical signal
in the first PON protocol.
13. The method according to claim 12, wherein denoising the first
optical signal comprises: converting the first optical signal into
a first electrical signal; performing protocol deframing on the
first electrical signal; performing protocol framing on a first
electrical signal obtained after protocol deframing; and performing
electrical-to-optical conversion on a first electrical signal
obtained after protocol framing, to obtain a processed first
optical signal; and wherein processing the second optical signal
comprises: converting the second optical signal into a second
electrical signal; performing protocol deframing on the second
electrical signal; performing protocol framing on a second
electrical signal obtained after protocol deframing; and performing
electrical-to-optical conversion on a second electrical signal
obtained after protocol framing, to obtain a processed second
optical signal.
14. The method according to claim 12, wherein denoising the first
optical signal comprises: parsing, by using the first PON protocol,
the first optical signal, and encapsulating a parsed first optical
signal by using the second PON protocol; and wherein processing the
second optical signal comprises: parsing, by using the second PON
protocol, the second optical signal, and encapsulating a parsed
second optical signal by using the first PON protocol.
15. The method according to claim 12, wherein a mode of sending a
processed second optical signal during the data upstream
transmission is a time division multiplexing (TDM) mode.
16. The method according to claim 12, wherein each of the first PON
protocol and the second PON protocol is one of a gigabit passive
optical network (GPON), an Ethernet passive optical network (EPON),
a 10G GPON, 10G EPON, or a time wavelength division multiplexing
(TWDM) PON protocol.
17. The method according to claim 12, wherein the customer-premises
equipment is one of an optical network unit (ONU) or an optical
network terminal (ONT).
Description
TECHNICAL FIELD
This application relates to the field of optical communications
technologies, and in particular, to a communications network and a
related device.
BACKGROUND
Current broadband access technologies are mainly categorized into
copper access technologies (for example, various DSL technologies)
and optical access technologies. An access network implemented by
using the optical access technology is referred to as an optical
access network (OAN).
A passive optical network (PON) is an implementation technology of
the optical access network, and the PON is an optical access
technology featuring point-to-multipoint transmission. A system
architecture of the PON is shown in FIG. 1.
In FIG. 1, an optical line terminal (OLT) is configured to provide
a network side interface for an OAN. The OLT is connected to an
upper-layer network side device (such as a switch or a router), and
is connected to one or more lower-layer optical distribution
networks (ODN).
The ODN includes a passive optical splitter configured for optical
power distribution, a feeder fiber connecting the passive optical
splitter to the OLT, and a distribution fiber connecting the
passive optical splitter to an optical network unit (ONU). During
data downstream transmission, the ODN transmits downstream data of
the OLT to each ONU by using the passive optical splitter.
Similarly, during data upstream transmission, the ODN aggregates
upstream data of the ONU and transmits the aggregated upstream data
to the OLT.
The ONU provides a user side interface for the OAN and is connected
to the ODN. If the ONU further provides a user port function, for
example, the ONU provides an Ethernet user port or a plain old
telephone service (POTS) user port, the ONU is referred to as an
optical network terminal (ONT).
As shown in FIG. 1, a conventional OLT is usually located in a
central office (CO), and the CO usually further includes a network
side device. The PON network shown in FIG. 1 is applicable to a
scenario in which the ONU and the ONT are deployed in an area such
as a city close to the central office.
With the popularization of broadband services, more ONUs and ONTs
are deployed in a remote area, and the OLT device needs to be
gradually deployed downstream from the central office to the remote
area such as a village or town. However, a conventional PON
networking mode shown in FIG. 1 cannot meet this requirement.
Therefore, how to construct a PON network to enable devices, such
as ONUs and ONTs, to be deployed in the remote area to support
broadband services is an urgent problem to be resolved.
SUMMARY
This application provides a communications network and a related
apparatus, so that a broadband service can be accessed in a remote
area, and transmission media can be saved and networking costs can
be reduced.
According to a first aspect, this application provides an optical
line terminal, including a processor, a memory, and a
communications apparatus, where the communications apparatus is
configured with a first PON interface and a second PON
interface;
during data downstream transmission, the communications apparatus
is configured to receive, through the first PON interface, a first
optical signal sent by a first optical line terminal; the processor
is configured to process the first optical signal; and the
communications apparatus is further configured to send a processed
first optical signal to customer-premises equipment through the
second PON interface; and
during data upstream transmission, the communications apparatus is
configured to receive, through the second PON interface, a second
optical signal sent by the customer-premises equipment; the
processor is configured to process the second optical signal; and
the communications apparatus is further configured to send a
processed second optical signal to the first optical line terminal
through the first PON interface.
Specifically, the first PON interface may be connected to an
upper-layer device of the optical line terminal, that is, the first
optical line terminal; and the second PON interface may be
connected to a lower-layer device of the optical line terminal,
that is, the customer-premises equipment.
The first PON interface and the second PON interface are ports that
are used for data connection in a communications network and for
which a PON technology is used. Different PON technologies or a
same PON technology may be used for the first PON interface and the
second PON interface. In other words, the first PON interface and
the second PON interface may correspond to different protocols or a
same PON protocol.
Two cases are provided below to describe a process in which the
processor processes an optical signal received by the optical line
terminal.
(1) The first PON interface and the second PON interface correspond
to different protocols.
When the first PON interface and the second PON interface are of
different types, the optical line terminal needs to perform
protocol conversion on the received optical signal for sending.
This application provides the following two conversion manners:
In a first manner, protocol conversion is directly performed on the
optical signal. In an optional embodiment, during data downstream
transmission, the processor is configured to: parse, by using a
protocol corresponding to the first PON interface, the first
optical signal received through the first PON interface, and
encapsulate a parsed first optical signal by using a protocol
corresponding to the second PON interface, to complete protocol
conversion of the first optical signal. During data upstream
transmission, the processor is configured to: parse, by using the
protocol corresponding to the second PON interface, the second
optical signal received through the second PON interface, and
encapsulate a parsed second optical signal by using the protocol
corresponding to the first PON interface, to complete protocol
conversion of the second optical signal.
In a second manner, after the optical signal is converted into an
electrical signal, protocol conversion is performed on the
electrical signal. In an optional embodiment, the optical line
terminal may further include an optical module, a first PON MAC
chip, and a second PON MAC chip. The first PON MAC chip uses a
protocol corresponding to the first PON interface, and the second
PON MAC chip uses a protocol corresponding to the second PON
interface.
During data downstream transmission, the processor is specifically
configured to: indicate the optical module to convert the first
optical signal received through the first PON interface into a
first electrical signal, indicate the first PON MAC chip to perform
protocol deframing on the first electrical signal, indicate the
second PON MAC chip to perform protocol framing on a first
electrical signal obtained after protocol deframing, and indicate
the optical module to perform electrical-to-optical conversion on a
first electrical signal obtained after protocol framing, to obtain
a processed first optical signal. Therefore, protocol conversion of
the first optical signal is completed.
During data upstream transmission, the processor is specifically
configured to: indicate the optical module to convert the second
optical signal received through the second PON interface into a
second electrical signal, indicate the second PON MAC chip to
perform protocol deframing on the second electrical signal,
indicate the first PON MAC chip to perform protocol framing on a
second electrical signal obtained after protocol deframing, and
indicate the optical module to perform electrical-to-optical
conversion on a second electrical signal obtained after protocol
framing, to obtain a processed second optical signal. Therefore,
protocol conversion of the second optical signal is completed.
(2) The first PON interface and the second PON interface correspond
to a same protocol.
When the first PON interface and the second PON interface have a
same type, the optical line terminal may perform processing, for
example, perform denoising and signal enhancement on the received
optical signal through the processor, to improve signal
transmission reliability.
In an optional embodiment, the communications apparatus is further
configured with an Ethernet interface. During data downstream
transmission, the communications apparatus is further configured to
receive, through the Ethernet interface, a first electrical signal
sent by a network side device; the processor is further configured
to convert the first electrical signal into a third optical signal;
and the communications apparatus is further configured to send the
third optical signal to the customer-premises equipment through the
second PON interface. During data upstream transmission, the
communications apparatus is further configured to receive, through
the second PON interface, a fourth optical signal sent by the
customer-premises equipment; the processor is further configured to
convert the fourth optical signal into a second electrical signal;
and the communications apparatus is further configured to send the
second optical signal to the network side device through the
Ethernet interface.
When being connected to an upper-layer device, the optical line
terminal in this application may be connected, through the first
PON interface, to a device (for example, a conventional optical
line terminal) that supports a downstream PON, and may be further
connected to the network side device such as a switch or a router
through the conventional Ethernet interface. Compared with the
conventional optical line terminal, the optical line terminal in
this application has more diversified application scenarios.
According to a second aspect, this application provides a
communications network, including a first optical line terminal, a
second optical line terminal, and customer-premises equipment,
where the first optical line terminal is connected to at least one
second optical line terminal through a PON interface, and the
second optical line terminal is connected to at least one
customer-premises equipment through the PON interface;
during data downstream transmission, the first optical line
terminal is configured to send a first optical signal to the at
least one second optical line terminal, and the second optical line
terminal is configured to process the first optical signal and send
a processed first optical signal to the at least one
customer-premises equipment; and
during data upstream transmission, the customer-premises equipment
is configured to send a second optical signal to the second optical
line terminal connected to the customer-premises equipment, and the
second optical line terminal is configured to process the second
optical signal and send at least one processed second optical
signal to the first optical line terminal.
The second optical line terminal may be the optical line terminal
provided in the first aspect. For a signal processing process
performed by the second optical line terminal, refer to related
descriptions of the optical line terminal in the first aspect.
Optionally, the communications network further includes a first
optical distribution network and a second optical distribution
network. The first optical distribution network may provide an
optical signal transmission path between the first optical line
terminal and the second optical line terminal. The second optical
distribution network may provide an optical signal transmission
path between the second optical line terminal and the
customer-premises equipment.
Further, optionally, the first optical distribution network may
include at least one optical splitter, and the second optical
distribution network may also include at least one optical
splitter. The at least one optical splitter in the first optical
distribution network may be configured to perform multi-level
splitting processing on an optical signal sent by the first optical
line terminal, and then send a processed optical signal to the
second optical line terminal, where a quantity of levels is related
to a quantity of optical splitters. Similarly, the at least one
optical splitter in the second optical distribution network may be
configured to: perform multi-level splitting processing on an
optical signal sent by the second optical line terminal, and then
send a processed optical signal to the customer-premises equipment,
where a quantity of levels is related to a quantity of optical
splitters. With an optical splitter, only one optical fiber may be
used to enable connection to an upper-layer device in an optical
distribution network. Then, a plurality of optical fibers are used
starting from the optical fiber, to connect to lower-layer devices.
Such a point-to-multipoint transmission mode can reduce
transmission medium overheads and networking costs.
In an optional embodiment, in the first distribution network, a
distance between the optical splitter and the second optical line
terminal is less than a distance between the optical splitter and
the first optical line terminal. The optical splitter is connected
to the first optical line terminal in the upstream through one
optical fiber, and is connected to a plurality of second optical
line terminals in the downstream through a plurality of optical
fibers. Therefore, when the optical splitter in the first
distribution network is disposed at a location closer to the second
optical line terminal, lengths of the plurality of optical fibers
can be shortened, and networking costs can be reduced.
In an optional embodiment, in the second optical distribution
network, a distance between the optical splitter and the
customer-premises equipment is less than a distance between the
optical splitter and the second optical line terminal. The optical
splitter is connected to the second optical line terminal in the
upstream through one optical fiber, and is connected to a plurality
of customer-premises equipment in the downstream through a
plurality of optical fibers. Therefore, when the optical splitter
in the second optical distribution network is disposed at a
location closer to the customer-premises equipment, lengths of the
plurality of optical fibers can be shortened, and networking costs
can be reduced.
The communications network in this application includes the first
optical line terminal, the second optical line terminal, and the
customer-premises equipment. The second optical line terminal may
be connected to a first optical line terminal at an upper layer
through the PON interface, and may be further connected to
customer-premises equipment at a lower layer through the PON
interface. The communications network in this application enables a
user in a remote area to access a broadband service. In addition,
the PON interface features point-to-multipoint transmission, and
therefore transmission media can be saved and networking costs can
be reduced.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a structural diagram of a PON network in the prior
art;
FIG. 2 is a structural diagram of another PON network in the prior
art;
FIG. 3 is a schematic diagram of a hardware structure of an optical
line terminal according to this application;
FIG. 4 is a schematic diagram of a form of an optical line terminal
according to this application;
FIG. 5 is a schematic diagram of a device form of another optical
line terminal according to this application;
FIG. 6 is a schematic diagram of a structure of a communications
network according to this application;
FIG. 7 is a schematic diagram of a structure of another
communications network according to this application;
FIG. 8 is a schematic diagram of a structure of still another
communications network according to this application;
FIG. 9 is a schematic flowchart of data downstream transmission in
a communications network according to this application;
FIG. 10 is a schematic flowchart of data upstream transmission in a
communications network according to this application; and
FIG. 11 is a functional block diagram of an optical line terminal
according to this application.
DESCRIPTION OF EMBODIMENTS
Terms used in implementations of this application are merely used
to explain specific embodiments of this application, but are not
intended to limit this application.
FIG. 2 is a structural diagram of a possible PON network in the
prior art. As shown in FIG. 2, OLT devices are not deployed in a
central office, but deployed closer to devices such as ONTs or
ONUs. The PON network shown in FIG. 2 may include more OLTs, to
enable more users in a remote area to access a broadband
service.
Although the PON network shown in FIG. 2 enables access to the
broadband service in the remote area, a network side device is
connected to the OLT through an Ethernet interface, and major
transmission media include a network cable, an optical fiber, and
the like. Because the Ethernet interface features point-to-point
transmission, an independent transmission medium needs to be
deployed between each OLT device and the network side device.
However, due to a relatively large quantity of OLT devices, a large
quantity of transmission media are required to deploy the PON
network shown in FIG. 2. Consequently, networking costs are
high.
To enable access to the broadband service in the remote area and
reduce networking costs, this application provides a PON network
and an optical line terminal, to provide the broadband service in
the remote area. In addition, networking costs are low, and this
application is easy to implement.
For ease of understanding this application, several technical terms
in this application are first described.
(1) PON Interface
A PON is a point-to-multipoint optical access technology. The PON
interface is a port that is used for data connection in a
communications network and for which the PON is used. A
transmission medium connected to the PON interface is an optical
fiber, and the PON interface may be configured to receive or send
an optical signal.
There are many types of PONs, such as an asynchronous transfer mode
PON (ATM passive optical network, APON), a broadband PON (broadband
passive optical network, BPON), an Ethernet PON (ethernet passive
optical network, EPON), a gigabit-capable PON (gigabit-capable
passive optical network, GPON), and a 10 Gbit/s Ethernet PON (10G
ethernet passive optical network, 10G EPON). Therefore, there may
also be many types of PON interfaces, such as a GPON interface, an
EPON interface, a symmetric 10G GPON interface, an asymmetric 10G
GPON interface, a 10G EPON interface, a TWDM PON interface, and a
future PON interface having a higher working rate.
It may be understood that different protocols may be used for
different PONs, and signal formats may be different when signals
are transmitted by using different PON technologies.
In this application, different types of PON interfaces correspond
to different protocols, and a signal that can be identified by the
PON interface and transmitted through the PON interface is a signal
encapsulated by using a corresponding protocol. Therefore, if a
device includes two PON interfaces of different types, protocol
conversion processing needs to be performed on a signal received
through one PON interface, and the signal can be sent through the
other PON interface only after the signal is encapsulated by using
a protocol corresponding to the other PON interface.
In this application, a type of a PON interface identifies a type of
an optical access technology used for the PON interface, and also
identifies a protocol corresponding to the PON interface.
It may be understood that the PON interface performs communication
in a point-to-multipoint manner. For example, as shown in FIG. 2,
the OLT is connected to customer-premises equipment through a PON
interface, and may be connected to a plurality of ONTs through one
PON interface. In other words, for a plurality of PON interfaces
connecting the OLT to customer-premises equipment in the
downstream, each PON interface may correspond to a plurality of
customer-premises equipment.
(2) Split Ratio
The split ratio is a concept specific to the PON interface and
indicates a quantity of customer-premises equipment that may be
with one PON interface. To be specific, the split ratio indicates a
quantity of customer-premises equipment that can be connected to
one PON interface. For example, a split ratio of a PON interface
defined in an EPON standard is 1:32, and split ratios of a PON
interface defined in a GPON standard are 1:32, 1:64, and 1:128. For
example, an EPON interface supports a maximum split ratio of 1:32.
The EPON interface may output a maximum of 32 channels of optical
signals, and the 32 channels of optical signals are transmitted to
32 different customer-premises equipment respectively.
It is clear that when communication is performed in the
communications network through the PON interface in the
point-to-multipoint manner, less transmission media are used and
costs are relatively low.
(3) Ethernet Interface
Ethernet is a most widely applied local area network communication
mode and is also a protocol. An Ethernet interface is a port that
is used for data connection in a network structure and for which
the Ethernet protocol is used. The Ethernet interface may be
configured to receive or send a signal, such as an Ethernet frame,
for which the Ethernet protocol is used.
The Ethernet interface mentioned in this application may include
various types, for example, includes at least one of an SC fiber
interface, an RJ-45 interface, an FDDI interface, an AUI interface,
a BNC interface, or a console interface. Transmission media
connected to the Ethernet interface may include a coaxial cable, a
twisted pair, an optical fiber, and the like.
The Ethernet interface performs communication in a point-to-point
manner. For example, as shown in FIG. 2, a switch is connected to
the OLT through an Ethernet interface. When there are a plurality
of OLTs, the switch needs to be connected to different OLTs through
different Ethernet interfaces. In other words, for a plurality of
Ethernet interfaces connecting the switch to the OLTs, each
Ethernet interface corresponds to only one OLT.
It is clear that when communication is performed in the
communications network through the Ethernet interface in the
point-to-point manner, more transmission media are used and costs
are relatively high.
FIG. 3 is a schematic diagram of a hardware structure of an optical
line terminal 300 according to this application. As shown in FIG.
3, the optical line terminal 300 mainly includes a processor 101, a
memory 102, a communications apparatus 103, and a power management
module 104.
The power management module 104 is configured to provide a stable
current for the optical line terminal 300.
The communications apparatus 103 may be configured for
communication between the optical line terminal 300 and another
communications device, for example, a network side device, another
optical line terminal, or customer-premises equipment. In this
application, the communications apparatus is configured with a
first PON interface and a second PON interface. The first PON
interface is configured for optical communication between the
optical line terminal 300 and an upper-layer device (another
optical line terminal at an upper layer). The second PON interface
is configured for optical communication between the optical line
terminal 300 and the customer-premises equipment. The first PON
interface and the second PON interface are ports using a PON
(passive optical network) technology for connection. The first PON
interface may include at least one of a GPON interface, an EPON
interface, a symmetric 10G GPON interface, an asymmetric 10G GPON
interface, a 10G EPON interface, a TWDM PON interface, or a future
PON interface having a higher working rate. The second PON
interface may include at least one of a GPON interface, an EPON
interface, a symmetric 10G GPON interface, an asymmetric 10G GPON
interface, a 10G EPON interface, a TWDM PON interface, or a future
PON interface having a higher working rate. Reference may be made
to a related description of the foregoing technical term (1).
Details are not described herein.
In this application, the first PON interface and the second PON
interface may be PON interfaces of different types, or may be PON
interfaces of a same type. The following describes functions of
modules in the optical line terminal 300 in different cases.
(1) The first PON interface and the second PON interface are PON
interfaces of different types.
Optionally, the first PON interface and the second PON interface
may be PON interfaces of different types. The processor 101 is
configured to perform protocol conversion processing on an optical
signal that is received through the first PON interface or the
second PON interface, so that a processed optical signal is adapted
to the second PON interface or the first PON interface. Two
conversion manners are described below.
In a first manner, protocol conversion is directly performed on the
optical signal. In an optional embodiment, during data downstream
transmission, the processor 101 is configured to: parse, by using a
protocol corresponding to the first PON interface, a first optical
signal received through the first PON interface, and encapsulate a
parsed first optical signal by using a protocol corresponding to
the second PON interface, to complete protocol conversion of the
first optical signal. During data upstream transmission, the
processor 101 is configured to: parse, by using the protocol
corresponding to the second PON interface, a second optical signal
received through the second PON interface, and encapsulate a parsed
second optical signal by using the protocol corresponding to the
first PON interface, to complete protocol conversion of the second
optical signal.
In a second manner, after the optical signal is converted into an
electrical signal, protocol conversion is performed on the
electrical signal. In an optional embodiment, the optical line
terminal 300 may further include an optical module 105, a first PON
MAC chip 106, and a second PON MAC chip 107. The first PON MAC chip
106 uses a protocol corresponding to the first PON interface, and
the second PON MAC chip uses a protocol corresponding to the second
PON interface.
During data downstream transmission, the processor 101 is
specifically configured to: indicate the optical module 105 to
convert a first optical signal received through the first PON
interface into a first electrical signal, indicate the first PON
MAC chip 106 to perform protocol deframing on the first electrical
signal, indicate the second PON MAC chip 107 to perform protocol
framing on a first electrical signal obtained after protocol
deframing, and indicate the optical module 105 to perform
electrical-to-optical conversion on a first electrical signal
obtained after protocol framing, to obtain a processed first
optical signal. In this way, protocol conversion of the first
optical signal is completed.
During data upstream transmission, the processor 101 is
specifically configured to: indicate the optical module 105 to
convert a second optical signal received through the second PON
interface into a second electrical signal, indicate the second PON
MAC chip 107 to perform protocol deframing on the second electrical
signal, indicate the first PON MAC chip 106 to perform protocol
framing on a second electrical signal obtained after protocol
deframing, and indicate the optical module 105 to perform
electrical-to-optical conversion on a second electrical signal
obtained after protocol framing, to obtain a processed second
optical signal. In this way, protocol conversion of the second
optical signal is completed.
(2) The first PON interface and the second PON interface are PON
interfaces of a same type.
When the first PON interface and the second PON interface have a
same type, the optical line terminal may perform processing, for
example, perform denoising and signal enhancement, on a received
signal through the processor, to improve signal transmission
reliability.
Optionally, the communications apparatus 103 may be further
configured with an Ethernet interface. The Ethernet interface is an
interface that performs communication by using an Ethernet
protocol, and may be configured for communication between the
optical line terminal 300 and an upper-layer network side device (a
switch, a router, or the like).
The memory 102 is coupled to the processor 101, and is configured
to store various software programs and/or a plurality of sets of
instructions. Specifically, the memory 102 may include a high-speed
random access memory, or may include a nonvolatile memory, for
example, one or more disk storage devices, a flash memory device,
or another nonvolatile solid-state storage device. The memory 102
may store an operating system (which is briefly referred to as a
system below), for example, an embedded operating system such as
Android, iOS, Windows, or Linux. The memory 102 may further store a
network communications program. The network communications program
may be used to communicate with one or more optical line terminals,
one or more customer-premises equipment, or one or more network
side devices.
The processor 101 may be configured to: read and execute a
computer-readable instruction; implement a function of managing the
optical line terminal 300; parse, control, or process a packet
received by the optical line terminal 300; and the like.
Specifically, the processor 101 may be configured to invoke a
program stored in the memory 102, and execute an instruction
included in the program. The instruction may be used for
implementing a function of signal transmission of the optical line
terminal 300 in a PON communications network.
It may be understood that the optical line terminal 300 may further
include an upstream board, a backplane that provides a physical
connection for each unit, a clock, a fan, a fan control module, and
the like. Details are not described herein.
It should be noted that the optical line terminal 300 shown in FIG.
3 is only an implementation of this application. In actual
application, the optical line terminal 300 may alternatively
include more or fewer components, and this is not limited
herein.
It can be learnt from the structure shown in FIG. 3 that, when
being connected to an upper-layer device, the optical line terminal
300 may be connected, through the first PON interface, to a device
(for example, a conventional optical line terminal) that supports a
downstream PON, or may be connected to a network side device such
as a switch or a router through a conventional Ethernet interface.
Compared with the conventional optical line terminal, the optical
line terminal 300 in this application has more diversified
application scenarios.
In specific implementation, there may be many actual forms of the
optical line terminal. The following briefly describes two possible
implementation forms of the optical line terminal.
In an optional embodiment, the optical line terminal 300 may be
implemented in a form of a box-type device or an integrated device.
Referring to FIG. 4, from the perspective of a protocol, the
optical line terminal includes one or more PON MAC chips configured
to process a communication service between the optical line
terminal and an upper-layer device. The PON MAC chip is configured
to implement a function of PON media access control (MAC) layer
protocol processing. The optical line terminal further includes a
component or chip configured to implement a forwarding function.
The component or chip may be configured to implement local area
network switch (LAN switch, LSW) forwarding, network processing
(NP), traffic management (TM), or the like. The optical line
terminal further includes one or more PON MAC chips configured to
process a communication service between the optical line terminal
and a lower-layer device. The PON MAC chip is configured to
implement a function of PON media access control (MAC) layer
protocol processing.
Optionally, the optical line terminal may further include one or
more ETH MACs/PHYs configured to process a communication service
between the optical line terminal and an upper-layer device. The
ETH MAC/PHY is configured to implement a function of Ethernet MAC
layer protocol processing/Ethernet physical layer protocol
processing during communication with the upper-layer device.
In another optional embodiment, the optical line terminal 300 may
be further implemented in a form of a frame-type device. Referring
to FIG. 5, the optical line terminal may include one or more
upstream access modules, one or more control modules, and one or
more downstream access modules.
The upstream access module provides a first PON interface. The
downstream access module provides a second PON interface. The
control module is configured to control the optical line terminal
to implement a function of protocol processing, packet switching,
packet forwarding, or the like.
Further, an upstream interface may further include a conventional
Ethernet interface, to enable the optical line terminal to be
applied to more optical communications scenarios.
Based on the optical line terminal 300 described above, this
application provides a communications network, to enable access to
a broadband service in a remote area and to reduce networking costs
during construction of the communications network.
A main inventive principle of this application may be as follows:
An optical line terminal includes a first PON interface used for
communicating with an upper-layer device. The first PON interface
may be used for point-to-multipoint communication between the
upper-layer device and a plurality of optical line terminals. This
can save transmission media and reduce networking costs.
FIG. 6 is a schematic diagram of a structure of a communications
network according to this application. The following separately
describes devices, connections between the devices, deployment
locations, a data transmission process, and the like in the
communications network in this application with reference to FIG.
6.
1. Connections Between the Devices
As shown in FIG. 6, the communications network includes a first
optical line terminal, a second optical line terminal, and
customer-premises equipment. The first optical line terminal is
connected to at least one second optical line terminal through a
PON interface, and the second optical line terminal is connected to
at least one customer-premises equipment through a PON
interface.
In this application, the first optical line terminal is connected
to the second optical line terminal through a PON interface, the
second optical line terminal is also connected to the
customer-premises equipment through a PON interface, and
transmission media are both optical fibers.
In an optional embodiment, the first optical line terminal and the
second optical line terminal may be connected through a first
optical distribution network, and the second optical line terminal
and the customer-premises equipment may be connected through a
second optical distribution network. Referring to FIG. 7, the first
optical distribution network may provide an optical signal
transmission path between the first optical line terminal and the
second optical line terminal. The second optical distribution
network may provide an optical signal transmission path between the
second optical line terminal and the customer-premises equipment.
Specifically, the first optical distribution network and the second
optical distribution network each may be implemented as an
intelligent ODN (iODN), an easy ODN, a smart ODN, or another type
of ODN. This is not limited in this application.
Further, in an optional embodiment, the first optical distribution
network may include at least one optical splitter, and an optical
fiber between the first optical line terminal and the second
optical line terminal. The second optical distribution network may
also include at least one optical splitter, and an optical fiber
between the second optical line terminal and the customer-premises
equipment. The optical splitter herein is a passive device, and is
used for downstream data distribution and upstream data
aggregation. The optical splitter has one upstream optical
interface and several downstream optical interfaces. Optical
signals from the upstream optical interface are distributed to all
of the downstream optical interfaces for transmission. Optical
signals from the downstream optical interfaces are aggregated to
the unique upstream optical interface for transmission.
It may be understood that the at least one optical splitter in the
first optical distribution network may be configured to: perform
multi-level splitting processing on an optical signal sent by the
first optical line terminal, and then send a processed optical
signal to the second optical line terminal, where a quantity of
levels is related to a quantity of optical splitters. Similarly,
the at least one optical splitter in the second optical
distribution network may be configured to: perform multi-level
splitting processing on an optical signal sent by the second
optical line terminal, and then send a processed optical signal to
the customer-premises equipment, where a quantity of levels is
related to a quantity of optical splitters. It is clear that, with
an optical splitter, only one optical fiber may be used to enable
connection to an upper-layer device in an optical distribution
network. Then, a plurality of optical fibers are used starting from
the optical fiber, to connect to lower-layer devices. Such a
point-to-multipoint transmission mode can reduce transmission
medium overheads and networking costs.
In a specific embodiment, referring to FIG. 7, the first optical
distribution network includes a first optical splitter, and the
second optical distribution network includes a second optical
splitter.
In the communications network shown in FIG. 6 or FIG. 7, the first
optical line terminal may be connected to a plurality of second
optical line terminals, and the second optical line terminal may be
further connected to a plurality of customer-premises equipment.
Compared with the communications network shown in FIG. 1, the
communications network shown in FIG. 6 or FIG. 7 enables access of
more customer-premises equipment. This expands a service scope.
Further, in the communications network shown in FIG. 6 or FIG. 7, a
plurality of levels of second optical line terminals may be
disposed. Referring to FIG. 8, the first optical line terminal is
connected to a plurality of second optical line terminals, and the
second optical line terminal may be further connected to another
second optical line terminal, and is connected to the
customer-premises equipment after a plurality of levels of
connections. A communications network shown in FIG. 8 enables
access of more customer-premises equipment. This expands a service
scope.
2. Implementation of the Devices
Specifically, in this application, the first optical line terminal
provides a PON interface used for communicating with a lower-layer
device (namely, the second optical line terminal). The first
optical line terminal may be a conventional optical line terminal
(namely, a conventional OLT), or may be the optical line terminal
shown in FIG. 3.
Specifically, the second optical line terminal provides not only a
PON interface used for communicating with a lower-layer device
(namely, the customer-premises equipment), but also a PON interface
used for communicating with an upper-layer device (namely, the
first optical line terminal). The first optical line terminal may
be the optical line terminal 300 shown in FIG. 3.
Specifically, the customer-premises equipment is a device that
sends Ethernet data to a user or receives Ethernet data sent by a
user, and may provide various broadband services for the user, such
as internet surfing, VoIP, HDTV, and video conference. In specific
implementation, the customer-premises equipment may be a device
such as an ONU or an ONT.
Specifically, the communications network shown in FIG. 6 is an
optical access network, the optical access network is connected to
a core network, and a network side device is a device that is in
the core network and that is directly connected to the optical
access network. In specific implementation, the network side device
may be a switch, a router, or the like.
3. Deployment Locations of the Devices
Specifically, the network side device is an important device in an
optical communications network, and is generally disposed in a
central office. In an optional embodiment, as shown in FIG. 6, both
the first optical line terminal and the network side device may be
disposed in the central office. In an optional embodiment, the
second optical line terminal may be disposed in a remote area
relatively far away from the central office. Because the second
optical line terminal is connected to lower-layer customer-premises
equipment, the customer-premises equipment in this application may
be deployed in a remote area such as a rural area relatively far
away from a city, to enable access to a broadband service in the
remote area.
In this application, optical splitters may be disposed based on an
existing standard. This is not limited in this application. The
following lists several possible cases of optical splitter
deployment as examples, but is not intended to limit this
application.
In an optional embodiment, the first optical line terminal and the
second optical line terminal are connected through the first
optical distribution network, and the first optical splitter is
disposed in the first optical distribution network. In this case, a
distance between the first optical splitter and the second optical
line terminal is less than a distance between the first optical
splitter and the first optical line terminal. In other words, the
first optical splitter is disposed at a location closer to the
second optical line terminal. The first optical splitter is
connected to the first optical line terminal in the upstream
through one optical fiber, and is connected to a plurality of
second optical line terminals in the downstream through a plurality
of optical fibers. Therefore, when the first optical splitter is
disposed at the location closer to the second optical line
terminal, lengths of the plurality of optical fibers can be
shortened, and networking costs can be reduced.
Further, when a plurality of optical splitters are disposed in the
first optical distribution network for multi-level splitting, the
plurality of optical splitters may be disposed based on an actual
situation and the existing standard. This is not limited in this
application.
Similarly, in an optional embodiment, the second optical line
terminal and the customer-premises equipment are connected through
the second optical distribution network, and the second optical
splitter is disposed in the second optical distribution network. In
this case, a distance between the second optical splitter and the
customer-premises equipment is less than a distance between the
second optical splitter and the second optical line terminal. In
other words, the second optical splitter is disposed at a location
closer to the customer-premises equipment. The second optical
splitter is connected to the second optical line terminal in the
upstream through one optical fiber, and is connected to a plurality
of customer-premises equipment in the downstream through a
plurality of optical fibers. Therefore, when the second optical
splitter is disposed at the location closer to the
customer-premises equipment, lengths of the plurality of optical
fibers can be shortened, and networking costs can be reduced.
Further, when a plurality of optical splitters are disposed in the
second optical distribution network for multi-level splitting, the
plurality of optical splitters may be disposed based on an actual
situation and the existing standard. This is not limited in this
application.
4. Data Transmission Process
In this application, the data transmission process includes a
downstream transmission process and an upstream transmission
process. In the downstream transmission process, a signal is sent
from the network side device to the customer-premises equipment. In
the upstream transmission process, a signal is sent from the
customer-premises equipment to the network side device.
Descriptions are separately provided below.
(1) Downstream Transmission Process
Referring to FIG. 9, the downstream transmission process may
include the following steps.
1. The first optical line terminal sends a first optical signal to
at least one second optical line terminal.
In this application, the first optical signal may be obtained by
converting an electrical signal received by the first optical line
terminal. The electrical signal is sent by the network side device
to the first optical line terminal through an Ethernet interface.
Specifically, the first optical line terminal is connected to the
network side device through the Ethernet interface. Generally, the
network side device sends an electrical signal to the first optical
line terminal. The first optical line terminal performs protocol
conversion on the received electrical signal, and performs
electrical-to-optical conversion on an electrical signal obtained
after protocol conversion, to obtain the first optical signal.
Then, the first optical line terminal sends, through a PON
interface, the first optical signal to the at least one second
optical line terminal connected to the first optical line
terminal.
In an optional embodiment, the communications network further
includes a first optical distribution network. The first optical
signal sent by the first optical line terminal may be transmitted
to the at least one second optical line terminal through the first
optical distribution network.
Further, in an optional embodiment, the first optical distribution
network includes a first optical splitter, and the first optical
signal sent by the first optical line terminal may be transmitted
to the at least one second optical line terminal through the first
optical distribution network by using the first optical
splitter.
2. The second optical line terminal processes the first optical
signal.
Specifically, after receiving the first optical signal through a
PON interface (for example, the first PON interface in FIG. 3)
connected to an upper-layer device, the second optical line
terminal performs protocol conversion processing on the first
optical signal, so that a processed first optical signal is adapted
to a PON interface connected to a lower-layer device.
Herein, for the protocol conversion processing operation performed
on the first optical signal by the second optical line terminal,
refer to a related description in FIG. 3, and details are not
described herein.
3. The second optical line terminal sends the processed first
optical signal to at least one customer-premises equipment.
In this application, the second optical line terminal sends the
processed first optical signal to the at least one
customer-premises equipment through the PON interface (for example,
the second PON interface in FIG. 3) connected to the lower-layer
device.
In an optional embodiment, the communications network further
includes a second optical distribution network. The processed first
optical signal sent by the second optical line terminal may be
transmitted to the at least one customer-premises equipment through
the second optical distribution network.
Further, in an optional embodiment, the second optical distribution
network includes a second optical splitter, and the processed first
optical signal sent by the second optical line terminal may be
transmitted to the at least one customer-premises equipment through
the second optical distribution network by using the second optical
splitter.
It may be understood that in a data downstream transmission
process, transmission is performed in a broadcast manner, and
processed first optical signals received by all customer-premises
equipment are the same. After receiving the first optical signal,
the customer-premises equipment may receive, based on
identification information carried in the first optical signal,
data belonging to the customer-premises equipment; and may further
perform optical-to-electrical conversion on the data, and then
transmit, to a terminal device (such as a computer) directly used
by a user, data obtained after optical-to-electrical
conversion.
The data downstream transmission process is completed through the
foregoing three steps. In the downstream transmission process, for
functions of the devices, refer to detailed descriptions of the
foregoing steps. Details are not described herein.
(2) Upstream Transmission Process
Referring to FIG. 10, the upstream transmission process may include
the following steps.
1. The customer-premises equipment sends a second optical signal to
the second optical line terminal connected to the customer-premises
equipment.
In this application, the second optical signal may be obtained by
converting an electrical signal received by the customer-premises
equipment. The electrical signal may be sent by a terminal device
(such as a computer) directly used by a user to the
customer-premises equipment through an Ethernet interface.
Specifically, the customer-premises equipment is connected to the
terminal device through the Ethernet interface. The terminal device
sends an electrical signal to the customer-premises equipment when
the terminal device needs to send data to a network side. The
customer-premises equipment performs protocol conversion on the
received electrical signal, and performs electrical-to-optical
conversion on an electrical signal obtained after protocol
conversion, to obtain the second optical signal. Then, the
customer-premises equipment sends, through a PON interface, the
second optical signal to the second optical line terminal connected
to the customer-premises equipment.
In an optional embodiment, the communications network further
includes a second optical distribution network. The second optical
signal sent by the customer-premises equipment may be transmitted,
through the second optical distribution network, to the second
optical line terminal connected to the customer-premises
equipment.
Further, in an optional embodiment, the second optical distribution
network includes a second optical splitter, and the second optical
signal sent by the customer-premises equipment may be transmitted,
through the second optical distribution network by using the second
optical splitter, to the second optical line terminal connected to
the customer-premises equipment.
2. The second optical line terminal processes the second optical
signal.
In this application, the second optical line terminal is connected
to a plurality of customer-premises equipment, and the second
optical line terminal may receive a plurality of second optical
signals. The plurality of second optical signals received by the
second optical line terminal may be different. Specifically, after
receiving the second optical signal through a PON interface (for
example, the second PON interface in FIG. 3) connected to a
lower-layer device, the second optical line terminal performs
protocol conversion processing on the second optical signal, so
that a processed second optical signal is adapted to a PON
interface connected to an upper-layer device.
Herein, for the protocol conversion processing operation performed
on the second optical signal by the second optical line terminal,
refer to a related description in FIG. 3, and details are not
described herein.
3. The second optical line terminal sends the processed second
optical signal to the first optical line terminal.
In this application, the second optical line terminal sends the
processed second optical signal to the at least one
customer-premises equipment through the PON interface (for example,
the first PON interface in FIG. 3) connected to the upper-layer
device.
In an optional embodiment, the communications network further
includes a first optical distribution network. The processed second
optical signal sent by the second optical line terminal may be
transmitted to the first optical line terminal through the first
optical distribution network.
Further, in an optional embodiment, the first optical distribution
network includes a first optical splitter, and the processed second
optical signal sent by the second optical line terminal may be
transmitted to the first optical line terminal through the first
optical distribution network by using the first optical
splitter.
It may be understood that in the data upstream transmission
process, transmission may be performed in a time division
multiplexing (TDM) mode.
It may be understood that, after receiving the second optical
signal, the first optical line terminal may further perform
optical-to-electrical conversion on the second optical signal, and
then transmit, to the network side device, an electrical signal
obtained after optical-to-electrical conversion.
The data upstream transmission process is completed through the
foregoing three steps. In the upstream transmission process, for
functions of the devices, refer to detailed descriptions of the
foregoing steps. Details are not described herein.
The foregoing describes in detail the communications network in
this application. FIG. 11 is a functional block diagram of an
optical line terminal according to this application. As shown in
FIG. 11, the optical line terminal may include a processing unit
111, a storage unit 112, and a communications unit 113. The
communications unit 113 is configured with a first PON unit and a
second PON unit.
During data downstream transmission, the communications unit 113 is
configured to receive, through the first PON unit, a first optical
signal sent by a first optical line terminal; the processing unit
111 is configured to process the first optical signal; and the
communications unit 113 is further configured to send a processed
first optical signal to customer-premises equipment through the
second PON unit.
During data upstream transmission, the communications unit 113 is
configured to receive, through the second PON unit, a second
optical signal sent by the customer-premises equipment; the
processing unit 111 is configured to process the second optical
signal; and the communications unit 113 is further configured to
send a processed second optical signal to the first optical line
terminal through the first PON unit.
It may be understood that the optical line terminal shown in FIG.
11 may be implemented as the second optical line terminal in any
one of FIG. 6 to FIG. 8. For functions of functional modules in the
optical line terminal, refer to FIG. 6 to FIG. 8 and related
descriptions. Details are not described herein.
In conclusion, the communications network in this application
includes a first optical line terminal, a second optical line
terminal, and customer-premises equipment. The second optical line
terminal may be connected to a first optical line terminal at an
upper layer through a PON interface, and may be further connected
to customer-premises equipment at a lower layer through a PON
interface. The communications network in this application enables a
user in a remote area to access a broadband service. In addition,
the PON interface features point-to-multipoint transmission, and
therefore transmission media can be saved and networking costs can
be reduced.
All or some of the foregoing embodiments may be implemented by
software, hardware, firmware, or any combination thereof. When
software is used to implement the embodiments, all or some of the
embodiments may be implemented in a form of a computer program
product. The computer program product includes one or more computer
instructions. When the computer instructions are loaded and
executed on a computer, all or some of the procedures or functions
according to this application are generated. The computer may be a
general-purpose computer, a dedicated computer, a computer network,
or another programmable apparatus. The computer instructions may be
stored in a computer-readable storage medium or may be transmitted
from a computer-readable storage medium to another
computer-readable storage medium. For example, the computer
instructions may be transmitted from a website, computer, server,
or data center to another website, computer, server, or data center
in a wired (for example, a coaxial cable, an optical fiber, or a
digital subscriber line) or wireless (for example, infrared, radio,
or microwave) manner. The computer-readable storage medium may be
any usable medium accessible by a computer, or a data storage
device, such as a server or a data center, integrating one or more
usable media. The usable medium may be a magnetic medium (for
example, a floppy disk, a hard disk, or a magnetic tape), an
optical medium (for example, a DVD), a semiconductor medium (for
example, a solid-state drive), or the like.
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